The invention relates to an insulation assembly which is used to insulate buildings and, for examples, to insulate floors, ceilings and the like of such buildings.
It is well known in the art to insulate buildings using various types of insulating materials including mineral fibers such as fibrous glass wool.
Prior art fibrous glass wool insulation often included combining a binder, such as a phenolic resin with glass wool subsequent to the fiberizing process. The resultant insulating material assembly had sufficient strength to support itself in long strips so that it could be, for example, placed between adjacent wall studs or ceiling trusses in a commercial or residential building.
Glass fiber insulation is generally made by laying down a blanket of multiple horizontal layers of glass fibers onto a moving belt. Very early on, in the industry, no binder was used. However, by the late 1930's and early 1940's the industry began to use an organic binder, such as the above-mentioned phenolic resin, which was thought to be necessary to give the insulation material structural integrity for handling, and to enable the blanket to recover its thickness and insulating value after being compressed during packaging and transportion. Thus, it is the current practice in the prior art to apply such binder materials to the fibers as the insulation blanket is being formed, and to partially compress and heat the resulting blanket to cure the binder and set the loft. The blanket is thereafter cut into batts or rolls and tightly compressed for packaging and transport.
Numerous types of binder compositions have been developed over the years as necessary components in prior art insulation assemblies.
The prior art teaches that a high recovery ratio in a fibrous glass batt having a low density is unexpected and not inherently found in binderless products of the past. McMillin and Sakarash U.S. Pat. No. 2,610,337 teaches the use of ultra-fine glass fibers to form soft, resilient mats for use as filling in cushions and the like. This prior art patent indicates that with such ultra-fine glass fibers, as much as 25 to 30% bonding agent may be used without causing undue stiffness. The patent states "although the bat becomes less resilient with decreased amounts of binder, as little as 5% by weight of the binder, when calculated on the weight of the finished product, has been successfully employed."